The present invention relates to an electromagnetically actuable fuel injection valve.
An electromagnetically actuable fuel injection valve is known comprising a valve housing, a valve seat body provided with a bore and a valve seat, a valve closing element extending into the bore to cooperate with the valve seat and which carries on its end remote from the valve seat an armature, a compression spring which urges the armature and the valve closing element toward the valve seat and an inner pole of a magnetic coil having a stop face located opposite the armature.
U.S. Pat. No. 4,700,891, which corresponds to DE-OS 35 35 124, has already disclosed a fuel injection valve of this kind. In the latter, an internal pole of a magnetic coil forms a direct stop surface for an armature of a valve closing element. The valve closing element has a needle-shaped valve closing body. Spherical valve closing bodies are also customary for fuel injection valves.
When the fuel injection valve is excited the valve closing element is displaced axially with the valve closing body to such an extent that the valve seat is cleared and the fuel can be sprayed. The displacement of the fuel closing body in the opening direction is effected by means of the force of the magnetic coil, through which current flows, on the armature. The motive friction of the valve closing body in the bore on the valve seat body, in particular in the case of canting as a result of skewing, leads to hysteresis errors in the driving of the fuel injection valve and skewing of the valve closing element additionally leads to a non-uniform fuel jet shape. This results in a degraded fuel preparation and differences in the fuel supply of the individual cylinders of internal combustion engines. The wear in the region of the valve seat and the armature caused by the canting leads to further functional impairments.